The present invention relates generally to configuration and management of computing devices and more specifically to a technique for remotely configuring, managing, and debugging a network device.
It is desirable to include a highly reliable management communication path to a network device to be used for configuring, managing and debugging the device. This typically takes the form (in a conventional wireless LAN (Local Area Network access point (AP)) of a dedicated console port connection to the CPU of the network device. Using a dedicated connection ensures that a reliable communication path is available even when the network device is not reachable using one of its native network interfaces. Native network interfaces may become unreachable due to misconfiguration, overflow of buffers or software runaway. A disadvantage to using a dedicated communication channel is that there is a cost burden associated with the extra cable, connector, transceiver, passive devices, additional space required on the device enclosure and additional area needed on the PCB (Printed Circuit Board). This additional cost burden becomes significant on lower cost/smaller form factor network devices such as wireless LAN access points. Furthermore the cost impact becomes significant when every network device includes such a dedicated connection.
In the past, the network administrator operating from a local computer could telephonically connect into the operating system of a remote server to monitor its health using a conventional communications package such as PC Anywhere or Procomm. This method required a third communications computer to be attached to the network. Typically, a connection would first be established from the local computer to the communications computer attached to the network of the server. If the server was operating, the network administrator would be prompted for a login password to access network resources, including the server. If the server was down, only the personal computer could be accessed (providing that PC had its own modem). After the administrator logged into the network, a server console utility, such as RCONSOLE, could be executed to gain access to the server. Because many times the server would be down, this method had limited usefulness. Additionally, only limited information was provided, since the server would have to be operating before the server console utility would operate.
Another technique that has been tried to reduce the cost burden of a dedicated console port interface is by using out of band communication signaling using unused pairs within the same Ethernet cable. However, this technique assumes that there are additional unused pairs available, which is not always true. Furthermore, this technique still requires some additional dedicated hardware for the management console interface.
Thus, the need exists for a reliable method for performing remote management of a networked device that does not require additional hardware. It would be desirable that the method be able to perform all functions ordinarily available to a console connection coupled directly to the network device. It would also be desirable for the method to be able to manage the device even when the device's native network interface is otherwise unreachable due to misconfiguration, overflow of buffers or software runaway.